摘要
采用原位法粉末装管工艺(in-situ PIT)制备了无定形碳掺杂MgB2/Nb/Cu超导线材并研究了该掺杂对MgB2微观结构及超导电性的影响。复合线材中以Nb作为阻隔层、Cu作为稳定体并采用冷拉拔工艺进行加工。研究了无定形碳掺杂对MgB2相形成、微观结构及超导电性的影响,其中掺杂量分别为MgB2-xCx(x=0.0,0.05,0.08,0.10,0.15)。分别采用XRD、SQUID、SEM/EDS及传输电流测试等方法对MgB2/Nb/Cu线材进行分析测试。XRD分析结果显示,700oC热处理后的线材可以获得纯度较高的MgB2超导相;微观结果照片显示无定形碳掺杂后可以获得良好的晶粒连接性;能谱分析表明掺杂物C元素均匀的分布在MgB2基体中;通过四引线法测试了传输临界电流密度Jc,在4.2K、5T,其Jc值高达1.4×105A/cm2;在4.2K、10T,其Jc值为3.3×104A/cm2。
The effects of amorphous carbon doping on superconducting properties of MgB2/Nb/Cu wires fabricated by the in-situ powder-in-tube（PIT） method have been investigated.Using Nb as the barrier and Cu as the stabilizer,the MgB2 wires were fabricated by cold drawing.The wires of MgB2-xCx（x = 0.0,0.05,0.08,0.10,0.15） have been investigated to realize the effect of amorphous carbon doping on the phase formation,microstructure and superconducting properties.Characterization of MgB2 /Nb/Cu wires was carried out using XRD,SQUID,SEM/EDS,and I c measurements.XRD result shows that the high purity MgB2 phase is acquired after heat-treatment at 700℃.The microstructure observation for wires shows that the MgB2 /Nb/Cu wires have better grain connectivity after doping amorphous carbon,and Energy Dispersive X-ray（EDS） analysis confirms the uniform distribution of carbon in the MgB 2 superconducting phase.The critical current density（J c） of wires was measured in different magnetic fields by a standard four probes method,and the transport J c values as high as 1.4 × 10 5 A/cm 2（4.2 K,5 T） and 3.3× 104 A/cm 2（4.2 K,10 T） have been achieved.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2012年第10期1709-1712,共4页
Rare Metal Materials and Engineering
基金
Nature Science Foundation of China(50877067)
National Basic Research Program of China(2011CBA00104)
